The Cell and Virus Core is designed to support two major activities of the NGEC: cell separations and analysis, and construction and production of self inactivating non-integrating lentiviral (NIL) vectors and viral stocks. AutoMACs and flow cytometry and sorting will be heavily utilized in Components 2-5 for LHE design, and in Components 6-8 for analysis of fluorescent reporter assays and immune function in in vivo gene targeting and repair experiments. NIL vectors will be used for delivery of LHE's and donor templates in selected experiments from Component 1, and in virtually all experiments proposed in Components 6-8.